Air Canada A320 taxiway overflight at SFO -Over 1,000 people were at imminent risk of serious injury or death

Incident
A near miss taxiway overflight of an Air Canada A320 plane last year could have been the “worst aviation accident in history,”, according to NTSB report.

“Over 1,000 people were at imminent risk of serious injury or death,” NTSB board member, Earl Weener, said

On July 7, 2017, about 23:56 LT, Air Canada flight 759, an Airbus A320-211, Reg.C-FKCK, with 135 passengers and 5 crew members, was cleared to land on runway 28R at San Francisco International Airport (SFO), San Francisco, California, but instead lined up with parallel taxiway C.1

Four airplanes (a Boeing 787, an Airbus A340, another Boeing 787, and a Boeing 737) were on taxiway C awaiting clearance to take off from runway 28R.

The incident airplane descended to an altitude of 100 ft above ground level and overflew the first airplane on the taxiway. The flight crew initiated a go-around, and the airplane reached a minimum altitude of about 60 ft and overflew the second airplane on the taxiway before starting to climb.

Captain said
According NTSB, The captain stated that, as the airplane approached the airport, he thought that he saw runway lights for runway 28L and thus believed that runway 28R was runway 28L and that taxiway C was runway 28R. At that time, the first officer was focusing inside the cockpit because he was programming the missed approach altitude and heading (in case a missed approach was necessary) and was setting (per the captain’s instruction) the runway heading, which reduced his opportunity to effectively monitor the approach. The captain asked the first officer to contact the controller to confirm that the runway was clear, at which time the first officer looked up. By that point, the airplane was lined up with taxiway C, but the first officer presumed that the airplane was aligned with runway 28R due, in part, to his expectation that the captain would align the airplane with the intended landing runway.

According to the captain, the first officer called for a go-around at the same time as the captain initiated the maneuver, thereby preventing a collision between the incident airplane and one or more airplanes on the taxiway. However, at that point, safety margins were severely reduced

Findings
1.The first officer did not comply with Air Canada’s procedures to tune the instrument landing system (ILS) frequency for the visual approach, and the captain did not comply with company procedures to verify the ILS frequency and identifier for the approach, so the crewmembers could not take advantage of the ILS’ lateral guidance capability to help ensure proper surface alignment.

2. The flight crew’s failure to manually tune the instrument landing system (ILS) frequency for the approach occurred because (1) the Flight Management System Bridge visual approach was the only approach in Air Canada’s Airbus A320 database that required manual tuning of a navigation frequency, so the manual tuning of the ILS frequency was not a usual procedure for the crew, and (2) the instruction on the approach chart to manually tune the ILS frequency was not conspicuous during the crew’s review of the chart.

3. The first officer’s focus on tasks inside the cockpit after the airplane passed the final waypoint reduced his opportunity to effectively monitor the approach and recognize that the airplane was not aligned with the intended landing runway.